The Denver Broncos have started to work running back Jamaal Charles into practice more and more in recent days, and that will be a key part of the team's decision about what to do with the 30-year-old four-time Pro Bowl selection.

To make their decision, the Broncos need information, and to gather that information, Charles has to be on the field. And that is why, much like for the Broncos' quarterbacks, this could be an important week for Charles to show what he can offer in the offense. The Broncos face the 49ers on Saturday night at Levi's Stadium in Santa Clara, California, and before that they have joint practices with San Francisco on Wednesday and Thursday mornings.

Asked recently if he needs to see Charles perform in a preseason game to project what he can offer the Broncos, coach Vance Joseph said, "Probably, yes. We've got San Fran this week, Emmanuel Sanders Jerseyswe've got Green Bay and even Arizona Week 4. Peyton Manning JerseysHe'll eventually play; it depends on the [team's medical staff] and how he's feeling."Charles has played in just eight games over the last two seasons because of multiple knee surgeries. Demaryius Thomas JerseysThe Broncos signed him to a one-year deal in free agency because they believed he could useful in certain situations, Von Miller Jerseysperhaps 10 to 12 plays a game. And what's not to like about the prospect of that? When healthy, Charles has had five 1,000-yard rushing seasons, four seasons with at least 40 receptions and four in which he scored at least eight touchdowns. DeMarcus Ware JerseysHe's averaged at least 5 yards per carry in eight of his nine NFL seasons.

No other back on the Broncos roster has had that kind of production. But health is a question given Charles' knee troubles, and the Kansas City Chiefs did not bring him back largely because they didn't think his knees could handle the wear and tear.

The Broncos held Charles out of virtually all of the on-field work in the offseason program and have gradually asked him to do more in training camp. Monday's work on the practice field likely was his most extensive thus far.